Higher Rates of Proximal Sessile Serrated Adenomas Among Whites Compared to Asians, Hispanics and Blacks

Abstract

Introduction: Surveillance, Epidemiology, End Results (SEER) data in the United States reveal that Whites rank third behind Blacks and American Indian/Alaska Natives for incidence and mortality from colorectal cancer. Sessile Serrated Adenomas (SSAs) have been proposed to play a role in the development of interval colorectal cancer; however, limited studies have assessed the prevalence of SSAs among Whites, Asians, Hispanics and Blacks. Our objective was to compare the prevalence of SSAs between Whites, Asians, Hispanics and Blacks using sessile serrated adenoma detection rate (SSADR) as a surrogate of prevalence. Methods: Colonoscopy quality data was collected prospectively at our single tertiary referral center from June 2012 to May 2017 using Qualoscopy (Docbot, Inc.). We included all diagnostic, screening and surveillance colonoscopies in Whites, Asians, Hispanics and Blacks over 40 years of age. Whites were compared to Asians, Hispanics and Blacks for detection of polyps (PDR), adenomas (ADR) and sessile serrated adenoma (SSADR) (Table 2). Subgroup analysis included colon location. Baseline characteristics included gender, age, BMI, bowel prep scores, bowel prep liters, total procedure time and cecal intubation rates (Table 1). Significance was determined by a two-tailed Fischer's exact test and T-test.Table: Table. Average Polyp Detection RatesTable: Table. Baseline CharacteristicsResults: 6085 colonoscopies met our inclusion criteria, of which 4448 were performed in Whites, 989 in Asians, 481 in Hispanics and 167 in Blacks. Overall, Whites had statistically higher rates of proximal sessile serrated adenomas (9.10%) compared to Asians (7.10%), Hispanics (3.70%) and Blacks (4.20%). Compared to Hispanics, Whites had significantly higher PDRs, ADRs, SSADRs within the entire colon and right colon and higher PDRs and ADRs within the left colon. Compared to Asians, Whites had significantly higher SSADRs within the entire colon but significantly lower ADRs within the left colon. Conclusion: Our data demonstrate significant racial differences in detections rates of polyps, adenomas and sessile serrated adenomas. Whites have higher proximal SSADRs compared to Asians, Hispanics and Blacks. Although Blacks have a higher incidence and mortality from colorectal cancer compared to Whites, we were unable to demonstrate increased prevalence of precancerous polyps in this group, perhaps due to the small sample size of our Black cohort. Larger studies are needed to verify our findings, which have significance relative to optimal screening and surveillance strategies.